iqbal: Allow caching of fft buffer and plan during the optimize call

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
master
Sylvain Munaut 10 years ago
parent e97293f89b
commit c0fd99fcd2
  1. 70
      src/iqbal.c

@ -98,22 +98,54 @@ osmo_iqbal_cxvec_fix(const struct osmo_cxvec *in, float mag, float phase,
return out;
}
/*! \brief Cache for \ref _osmo_iqbal_estimate when doing lots of calls */
struct _iqbal_estimate_state {
float complex *fft; /*!< \brief Temporary memory for FFT */
fftwf_plan fft_plan; /*!< \brief FFTW plan */
};
/*! \brief Release a cache object created by \ref _osmo_iqbal_estimate */
static void
_osmo_iqbal_estimate_release(struct _iqbal_estimate_state *state)
{
if (!state)
return;
fftwf_destroy_plan(state->fft_plan);
free(state->fft);
free(state);
}
/*! \brief Objectively estimate IQ balance in a given complex buffer
* \param[in] data Input complex buffer (at least fft_size * fft_count samples)
* \param[in] fft_size Size of the FFT to use internally
* \param[in] fft_count The number of consecutive FFT to use internally
* \param[out] state_p Cache object for multiple calls (can be NULL)
* \returns A number >= 0.0f estimating the IQ balance (the lower, the better)
*
* The Cache object should only be used for multiple calls with the same parameters
* and the same size of input vector. Once you don't plan on using it anymore,
* you should call \ref _osmo_iqbal_estimate_release . The initial pointer value
* should also be initialized to NULL.
*/
float
osmo_iqbal_estimate(const float complex *data, int fft_size, int fft_count)
static float
_osmo_iqbal_estimate(const float complex *data, int fft_size, int fft_count,
struct _iqbal_estimate_state **state_p)
{
float complex *fft;
float est = 0.0f;
fftwf_plan fft_plan;
int i, j;
fft = malloc(sizeof(float complex) * fft_size);
fft_plan = fftwf_plan_dft_1d(fft_size, fft, fft, FFTW_FORWARD, FFTW_ESTIMATE);
if (state_p && *state_p) {
fft = (*state_p)->fft;
fft_plan = (*state_p)->fft_plan;
} else {
fft = malloc(sizeof(float complex) * fft_size);
fft_plan = fftwf_plan_dft_1d(fft_size, fft, fft, FFTW_FORWARD, FFTW_ESTIMATE);
}
for (i=0; i<fft_count; i++)
{
@ -130,12 +162,30 @@ osmo_iqbal_estimate(const float complex *data, int fft_size, int fft_count)
/* est /= fft_count; */
fftwf_destroy_plan(fft_plan);
free(fft);
if (state_p && !*state_p) {
*state_p = malloc(sizeof(struct _iqbal_estimate_state));
(*state_p)->fft = fft;
(*state_p)->fft_plan = fft_plan;
} else if (!state_p) {
fftwf_destroy_plan(fft_plan);
free(fft);
}
return est;
}
/*! \brief Objectively estimate IQ balance in a given complex buffer
* \param[in] data Input complex buffer (at least fft_size * fft_count samples)
* \param[in] fft_size Size of the FFT to use internally
* \param[in] fft_count The number of consecutive FFT to use internally
* \returns A number >= 0.0f estimating the IQ balance (the lower, the better)
*/
float
osmo_iqbal_estimate(const float complex *data, int fft_size, int fft_count)
{
return _osmo_iqbal_estimate(data, fft_size, fft_count, NULL);
}
/*! \brief Objectively estimate IQ balance in a given complex vector
* \param[in] sig Input complex vector (at least fft_size * fft_count samples)
* \param[in] fft_size Size of the FFT to use internally
@ -172,6 +222,7 @@ struct _iqbal_state
const struct osmo_cxvec *org; /*!< \brief Original vector */
struct osmo_cxvec *tmp; /*!< \brief Temporary vector */
int feval; /*!< \brief # of function evaluation */
struct _iqbal_estimate_state *cache; /*!< \brief Cache for estimate func */
};
/*! \brief Optimization objective function - Value
@ -184,8 +235,9 @@ _iqbal_objfn_value(struct _iqbal_state *state, float x[2])
{
state->feval++;
osmo_iqbal_cxvec_fix(state->org, x[0], x[1], state->tmp);
return osmo_iqbal_cxvec_estimate(state->tmp,
state->opts->fft_size, state->opts->fft_count);
return _osmo_iqbal_estimate(state->tmp->data,
state->opts->fft_size, state->opts->fft_count,
&state->cache);
}
/*! \brief Optimization objective function - Gradient estimation
@ -256,6 +308,7 @@ osmo_iqbal_cxvec_optimize(const struct osmo_cxvec *sig, float *mag, float *phase
state->tmp = osmo_cxvec_alloc(sig->len);
state->opts = opts;
state->feval = 0;
state->cache = NULL;
if (opts->start_at_prev) {
cx[0] = *mag;
@ -290,6 +343,7 @@ osmo_iqbal_cxvec_optimize(const struct osmo_cxvec *sig, float *mag, float *phase
}
osmo_cxvec_free(state->tmp);
_osmo_iqbal_estimate_release(state->cache);
*mag = cx[0];
*phase = cx[1];

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